Updated formula: dnsmasq. Add a launchd item and a sample config file

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Formula/dnsmasq.rb

@@ -7,6 +7,47 @@ class Dnsmasq <Formula
 
   def install
     ENV.deparallelize
+
+    inreplace "src/config.h", "/etc/dnsmasq.conf", "#{etc}/dnsmasq.conf"
     system "make install PREFIX=#{prefix}"
+
+    prefix.install "dnsmasq.conf.example"
+    (prefix + "uk.org.thekelleys.dnsmasq.plist").write startup_plist
+  end
+
+  def caveats; <<-EOS.undent
+    To configure dnsmasq, copy the example configuration to #{etc}/dnsmasq.conf
+    and edit to taste.
+
+      cp #{prefix}/dnsmasq.conf.example #{etc}/dnsmasq.conf
+
+    To load dnsmasq automatically on startup, install and load the provided launchd
+    item as follows:
+
+      sudo cp #{prefix}/uk.org.thekelleys.dnsmasq.plist /Library/LaunchDaemons
+      sudo launchctl load -w /Library/LaunchDaemons/uk.org.thekelleys.dnsmasq.plist
+    EOS
+  end
+
+  def startup_plist; <<-EOS.undent
+    <?xml version="1.0" encoding="UTF-8"?>
+    <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+    <plist version="1.0">
+      <dict>
+        <key>Label</key>
+        <string>uk.org.thekelleys.dnsmasq</string>
+        <key>ProgramArguments</key>
+        <array>
+          <string>/usr/local/sbin/dnsmasq</string>
+          <string>--keep-in-foreground</string>
+        </array>
+        <key>KeepAlive</key>
+        <dict>
+          <key>NetworkState</key>
+          <true/>
+        </dict>
+      </dict>
+    </plist>
+    EOS
   end
 end